Explain call by reference, C/C++ Programming

Assignment Help:

Call by Reference

Passing variables(parameters) to a function in C can be done in two ways - pass by value, also called as call by value and pass by address or also known as call by address. C++ though , gives one more way to call a function - call by reference. In call by value , a copy of the actual contents of the variables is passed to the function. In this case, alters made to the formal variable , as they are called, are not reflected back in the calling function. Passing an address permits changes to be made directly to the memory, which are occupied by the actual variable.

Though, a call by address requires the formal variable to be considered as pointer and therefore the indirection operator has to be used with them. A reference on the other hand, is another name, for a previously explained variable. In other words, after a reference is explained for a particular variable, using its original name as well as the reference can refer to the variable. Hence, a reference is nothing but an alias.

 Thus not passing a copy (call by value) saves time and is efficient. It does not have to make a temporary variable /. And not passing the address(call by address), eliminates the use of pointers in the called functions. But, at the same time, the changes made to a formal variable , using its reference or alias can be reflected back in the calling function.

 


Related Discussions:- Explain call by reference

Programming Exercise 3, I have an exercise with 2 problems. One that is par...

I have an exercise with 2 problems. One that is partially completed except with read problems with memory overwrite, and the other problem. I have enclosed the instructions documen

Padovan string, find the occurence of zy in the final string

find the occurence of zy in the final string

Stream input and output functions, Within C we access external devices by ...

Within C we access external devices by means of a pointer i.e. address. The address could point to any memory mapped device i.e. Ram, Rom, Duart, Disk drives etc. Therefore there i

How do you know that your class requires virtual destructor, How do you kn...

How do you know that your class requires a virtual destructor? A: If at least your class has one virtual function, you must make a destructor for this class virtual. It will let

Program for design and simulate a basic risc processor, Overall Program Obj...

Overall Program Objective: You will design and simulate a basic RISC processor.   You will create and encode an instruction set.  Your final task will be to "compile" a program

Program, First line starts with T, number of test cases. Each test case T c...

First line starts with T, number of test cases. Each test case T contains a necklace (N).

Define internal static storage class - computer programming, Define Interna...

Define Internal static storage class - computer programming? The Internal static variables are those that declared inside a function. The scope of the internal static variables

String-classes-constructors and member functions, Objective Using C++ s...

Objective Using C++ string, classes, constructors and member functions. Task A Write a program (book.cpp) to store a list of book titles and the published dates. Your pro

How to write program, how to write a program for all the types of beam reac...

how to write a program for all the types of beam reactions

Simplify the logical phrase with C++, hi i want wite a C++ program that get...

hi i want wite a C++ program that get one logical phrase (included {x,y,z,w,1,0}) and simplify it! but i ''m confused! thanxs for anubody help me...

Write Your Message!

Captcha
Free Assignment Quote

Assured A++ Grade

Get guaranteed satisfaction & time on delivery in every assignment order you paid with us! We ensure premium quality solution document along with free turntin report!

All rights reserved! Copyrights ©2019-2020 ExpertsMind IT Educational Pvt Ltd